For 1., also don't forget that major labour movements spring up during and after WW2, it's hard to say how much of a repeat that will be this time around, but the potential is there

And 2., I agree, I am concerned myself, especially with nukes these days

But on the other hand, economy, and reliance on globalized production chains, is so much more central to the core of a nation these days. It's not possible to just produce everything locally anymore, not like it was during WW2, anyway. everything is too hyper specialized for that now

So there is the potential that, if the US really does something very stupid and gets a complete embargo from the rest of the west, they're just going to get completely fucked (and so will the rest of the west, but you know). So the amount of damage they end up being able to do might end up being limited

Of course, China would benefit massively from this, as they do actually go heavy on self-sufficiency, and then there's the risk of Russia exploiting this as well, but the silver lining is that the US simply might collapse before it manages to do some real damage

In the end, I think the future of how the world will look like will be up to China. I really really hope that they end up having a massive democratic movement for the sake of the world, but we'll see. At least China so far still seems like a rational actor on the world stage, although still ruthless and self-serving, of course